1. Department of Medicine, University of Ioannina, 45 110 Ioannina, Greece
2. Division of Cardiovascular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford OX3 9DU, UK
3. Section of Interventional Cardiology, MedStar Washington Hospital Center, Washington, DC 20010, USA
4. Department of Therapeutics, Faculty of Medicine, National and Kapodistrian University of Athens, 157 72 Athens, Greece
5. Catheterization and Hemodynamic Unit, Alexandra University Hospital, 115 28 Athens, Greece